[Guillain-Barré syndrome and its variants: Miller-Fisher syndrome. Description of a clinical case in pediatric age.]

Miller-Fisher syndrome is a rare acquired nerve disease related to Guillain-Barré syndrome. Clinical features include asthenia, ocular muscle weakness with ophthalmoplegia, impaired limb coordination with instability, and absence of tendon reflexes. Swallowing disorders and rarely respiratory failure may be associated. The article aims to summarize, starting from the presentation of a clinical case, the latest updates which, in clinical practice, can be useful for a correct diagnosis and treatment of this condition which concerns both adult and pediatric patients.

Perampanel as precision therapy in rare genetic epilepsies

OBJECTIVE

Perampanel, an antiseizure drug with α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor antagonist properties, may have a targeted effect in genetic epilepsies with overwhelming glutamate receptor activation. Epilepsies with loss of γ-aminobutyric acid inhibition (e.g., SCN1A), overactive excitatory neurons (e.g., SCN2A, SCN8A), and variants in glutamate receptors (e.g., GRIN2A) hold special interest. We aimed to collect data from a large rare genetic epilepsy cohort treated with perampanel, to detect possible subgroups with high efficacy.

METHODS

This multicenter project was based on the framework of NETRE (Network for Therapy in Rare Epilepsies), a web of pediatric neurologists treating rare epilepsies. Retrospective data from patients with genetic epilepsies treated with perampanel were collected. Outcome measures were responder rate (50% seizure reduction), and percentage of seizure reduction after 3 months of treatment. Subgroups of etiologies with high efficacy were identified.

RESULTS

A total of 137 patients with 79 different etiologies, aged 2 months to 61 years (mean = 15.48 ± 9.9 years), were enrolled. The mean dosage was 6.45 ± 2.47 mg, and treatment period was 2.0 ± 1.78 years (1.5 months-8 years). Sixty-two patients (44.9%) were treated for >2 years. Ninety-eight patients (71%) were responders, and 93 (67.4%) chose to continue therapy. The mean reduction in seizure frequency was 56.61% ± 34.36%. Sixty patients (43.5%) sustained >75% reduction in seizure frequency, including 38 (27.5%) with >90% reduction in seizure frequency. The following genes showed high treatment efficacy: SCN1A, GNAO1, PIGA, PCDH19, SYNGAP1, POLG1, POLG2, and NEU1. Eleven of 17 (64.7%) patients with Dravet syndrome due to an SCN1A pathogenic variant were responders to perampanel treatment; 35.3% of them had >90% seizure reduction. Other etiologies remarkable for >90% reduction in seizures were GNAO1 and PIGA. Fourteen patients had a continuous spike and wave during sleep electroencephalographic pattern, and in six subjects perampanel reduced epileptiform activity.

SIGNIFICANCE

Perampanel demonstrated high safety and efficacy in patients with rare genetic epilepsies, especially in SCN1A, GNAO1, PIGA, PCDH19, SYNGAP1, CDKL5, NEU1, and POLG, suggesting a targeted effect related to glutamate transmission.

[Hashimoto's encephalopathy: when the thyroid gland makes you dream. Description of a clinical case and literature review.]

Hashimoto's encephalopathy (HE) is a rare condition in the childhood. It can present with neurological symptoms, psychiatric disorder or seizures. It is more frequently associated with hypothyroidism or euthyroidism, but it can occur, more rarely, even in hyperthyroidism. The presence of serum thyroid (thyroid peroxidase, thyroglobulin) antibodies is a criterion for the diagnosis of HE. We present the case of an 11-years-old girl with HE with seizures associated with hyperthyroidism with an excellent response to a high dose of steroids.

[Encephalitis by type B influenza: a pediatric clinical case and literature review.]

We report the case of a 6-year-old girl who presented with encephalitis during type B influenza. The clinical picture was characterized by an alteration of the state of consciousness associated with focal neurological signs with electroencephalographic changes and brain MRI. Clinical improvement was rapid and without neurological outcomes. The clinical characteristics, the pathogenic mechanisms, the prognosis and the therapy of neuroinfluenza cases are described.

8q12 microduplication including CHD7: clinical report on a new patient with Duane retraction syndrome type 3

Background

A novel multiple congenital anomalies syndrome has been recently identified in four patients carrying a 8q12 microduplication sharing the smallest region of overlap (SRO, size 1.6 Mb) including five genes CA8, ASPH, RAB2B, CLVS1 and CDH7. The phenotype is mainly characterized by neurodevelopmental delay, heart defects, facial features and Type 1 Duane anomaly. Increasing dosage of CDH7 was proposed to be responsible for the recurrent pattern of MCA.

Results

High resolution array-CGH analysis identified a 4.2 Mb de novo interstitial duplication of the 8q12.1-q12.3 chromosome region in a boy with developmental delay, dysmorphic features, type 3 Duane anomaly. This duplication includes several genes and spans the SRO.

Discussion

The present case represents a further patient with an interstitial duplication of chromosome 8q12 and several shared clinical features. Although more cases are needed to delineate the full-blown phenotype of 8q12 duplication syndrome, published data and present observations suggest that it results in a clinically recognizable phenotype. The presence of Duane anomaly in four out of five described patients with a 8q12 duplication definitely rules against the possibility of its being a chance finding unrelated to the imbalance and points toward a pathogenic role. Gene content analysis of the duplicated region and review of the literature suggest that gain-of-dosage of the CHD7 gene may be a good candidate for the main clinical features of the syndrome.

Focusing attention on overlapping and non-overlapping figures with subjective contours

In a series of five experiments we investigated whether observers could focus attention on a restricted visual area that was demarcated by Kanizsa-like subjective contours, and whether this effect also occurred in the case of overlapping figures. The task was a simple reaction time to a luminance increment and the basic finding was that reaction time was faster when the imperative stimulus fell inside the focus of attention than when it fell outside. The first two experiments showed that the extent of the attentional focus could be adapted to a region that was demarcated by subjective contours, thus extending the results of previous studies that used regions demarcated by real contours. The last three experiments showed that, regardless of the type of margins, focusing was more efficient for the figure that was perceived as lying in front in a pair of overlapping figures.

The positive and negative of human expertise in gaze perception

Judging where others look is crucial for many social and cognitive functions. Past accounts of gaze perception emphasize geometrical cues from the seen eye. Human eyes have a unique morphology, with a large white surround (sclera) to the dark iris that may have evolved to enhance gaze processing. Here we show that the contrast polarity of seen eyes has a powerful influence on gaze perception. Adult observers are highly inaccurate in judging gaze direction for images of human eyes with negative contrast polarity (regardless of whether the surrounding face is positive or negative), even though negative images of eyes preserve the geometric properties of positives that are judged accurately. The detrimental effect of negative contrast polarity is much larger for gaze perception than for other directional judgements (e.g. judging which way a head is turned). These results suggest an 'expert' system for gaze perception, which always treats the darker region of a seen eye as the part that does the looking.

[Separation of N-acetyl-beta-hexosaminidase isoenzymes. Methological note]

We examined the activity of total N-acetyl-beta-hexosaminidase and of its isoenzyme forms, that represent different stages of the maturation of the lysosomal hydrolase. In both methods the enzyme catalyzes the separation of 4-methylumbelliferone, a fluorescent substance, from 4-methylumelliferyl-2-acetamido-2-deoxy-beta-D-glucopyranoside. We used Leaback's method for the fluorimetric assay of total enzyme, and Ellis's DEAE-cellulose microcolum chromatography for the assay of its components. We obtained a clear separation of each fraction. We will apply these methods in our further studies of children with renal damage, because hexosaminidase seems to be one of the most sensitive markers of tubular damage.